Gas-engine



Patented Mar. l4, I899. L. J. HIRT.

GAS ENGINE.

(Application filed. Oct. 30; 1897.)

4 Sheets-Sheet I.

(No Model.)

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No. 620,926. Patented-Mann, I899. L. J. mm.

GAS ENGINE.

(Applicstipn filed Oct. 30, 1897.; (N0 lludel.) 4, Sheets8heet 2'.

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' Patented Mar. l 4, I899. L. J. HIRT.

GAS ENGINE.

(Application filed Oct. 80, 1897.)

(No Model.)

4 Sheets$haet 3.

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- No. 620,926.' Patented Mar. I4, I899.

L. J. HIBT.

'GAS ENGINE.

(Application filed Oct. 30, 1897.)

4 Sheets-Sheet 4.

(No Model.)

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NrTn STATES PATENT FFICE.

LOUIS J. HIRT, OF BROOKLINE, MASSACHUSETTS.

GAS-ENGINE.

SPECIFICATION forming part of Letters Patent No. 620,926, dated March 14, 1899.

Application filed October 30, 1897. Serial No. 656,894. (No model.) 7

To all whom it may concern:

Be it known that I, L'oUIs J. HIRT, residing in Brookline, in the county of Norfolk and State of Massachusetts, have invented an Improvement in Gas-Engines, of which the following description, in connection with the accompanying drawings, is a specification, like letters and figures on the drawings representing like parts. 1

This invention relates to gas-engines, and has for its objectto provide an engine which is capable of operating as a constant-pressure engine and of being automatically converted into a variable-pressure engine by diminution of the pressure of the gas employed to run the engine. In accordance with this invention the engine may be started under a constant pressure and run as a constant-pressure engine, gas being admitted and exploded at each stroke of the engine until the engine is running in the desired or proper manner, and when it is so running the supply of gas and air at a reduced pressure may be admitted to the engine-cylinder, and the engine responds to the diminution in the pressure of the gas and automatically converts itself into a variable-pressure engine in which the gas is exploded once for every two complete reciprocations of the piston.

In the present instance I have embodied my invention in a double-acting engine of the well-known Corliss type in order that the operation of the engine may be clearly shown and easily understood; but I do not desire to limit my invention to this particular type of engine, as it can be embodied in other well-known forms of engines.

In accordance with this invention the admission and exhaust valves for the engine are adapted to be operated at each stroke of the piston when the latter is running under a constant pressure, but are controlled automatically, as will be described, by the pressure of the gas, so as not to be operated on alternate strokes of the piston when the engine is running under a variable pressure of the gas. The gas-admission valves are also further controlled by a governor which automatically regulates the amount of gas admitted into the cylinder according to the speed of the engine. The engine is provided with igniters for the gas, which are autoexhaust-valves a a".

matically controlled, as will be described, so as to eifect an explosion of the gas at each reciprocation of the piston when the engine is running under constant pressure and at alternate reciprocations of the piston when the engine is running under a variable pressure. These and other features of this invention will be pointed out in the claims at the end of this specification.

Figure 1 is a top or plan view of a gas-em gin-e embodying this invention; Fig. 2, afront elevation of the engine shown in Fig. 1; Fig. 3, a detail, on a larger scale and in front elevation, of the right-hand portion of the engine shown in Fig. 2; Fig. 4, a sectional gletail on the line 4 4, Fig. 1; Fig. 5, a detail of the valve-operating mechanism to be referred to; Fig. 6, a top or plan view of the mechanism shown in Fig. 5 Figs. 7, 8, and 9, details to be referred to, Fig. 9 being a section on the line 9 9, Fig. 8; Figs. 10 and 11, details to be referred to; Fig. 12, a sectional detail, on an enlarged scale, on the line 12 12, Fig. 1; and Figs. 13, 14, 15, 16, 17, 18, and 19, details to be referred to, Fig. 15 being a section on the line 15 15, Fig. 6, looking toward the right.

In the present embodiment of this invention A represents the cylinder of the engine, provided with water jackets or spaces A at its ends and around its body portion and with the piston A (see dotted lines, Fig. 1,) having its piston-rod A joined by the connecting-rod A to a crank-pin A on a crank or disk A", fast on the main shaft A having bearings in the base or framework A The cylinder A has secured to it, preferably on one side at its opposite ends, two sets of Valve-casings a a, a (t the casings a a containing the gas-admission valves a a (see Fig. 3) and the casings a a containing the The valves a a a a are preferably made as piston-valves cooperating with suitable seats in their respective valve-casings and provided with valve-rods a a a e (see Fig. 3,) which are extended up through the heads or upper ends of the valve-casings and each of which is secured to an actuating mechanism, as will be described. .Inasmuch as the actuating mechanisms for all the valves are the same, I will specifically. describe the construction of but one, which may be supposed to be that which operates the admission-valve a The actuating mechanism referred to consists, essentially, of a rock-shaft a (see Figs. 5, (3, and 15,) having a bearing in a standard or upright (621, erected upon the head of the valvecasing. The rock-shaft (1 at one end has fast on it a crank or arm (0 having its end rounded or provided with a ball a, (see Figs. 0, 18, and 19,) which enters a slot or in the end of a bar or red (L25, fastened to the valvestem a so that when the rock-shaft a is moved in the direction indicated by the arrow 20, Fi 5, the valve a will be lifted from its seat, so as to permit the gas or gas and air to pass into the cylinder A. The rock-shaft (L20 at its opposite end has fast on it a second crank or arm a carrying a bolt (Z31, provided with a square or other than round head a, (see dotted lines, Figs. 0 and 16,) which is adapted to be engaged by an arm a provided with a latch or hook a and fast on a shaft cfiflhaving bearings in a hub cfflattached to a crank or arm a iextended from the sleeve or hub (L39, loosely mounted on the end 2 of the bearing-hub for the rock-shaft a and provided with a second arm or crank a The sleeve or hub a is adapted to be operated by an eccentric a on the main shaft A and which eccentric for the purpose of this invention I prefer to designate as the main eccentric. The eccentric a, as shown in Fig. 2, is joined by a rod a to a lever a, pivoted to the framework and connected by a rod to to a wrist-plate 0, pivotally mounted on a stud or bracket a attached to the side of the cylinder A. (See Fig. 1.) The wrist-plate a is joined by a link or red a to the crank or arm (0 From the above description it will be seen that at each revolution of the main shaft A the crank or arm a of the sleeve a will be actuated to lift the valve a if the latch or hooked arm a is in position to engage the head c0 of the belt a. When the engine is running as a constant-pressure engine at normal speed, the latch or arm (L is .in proper position at all times to engage the head (0 of the bolt and lift the Valve once for every revolution of the main shaft, and consequently lift the valve once for every complete reciprocation of the piston A The latch-arm c0 is held in its proper position until positively removed therefrom by tripping devices or mechanisms, as will be described, by means of a spring a attached at one end to the crank or arm a. (See Fig. 5.)

In order to enable the engine to be automatically converted from aeonstant-pressure engine into a variable-pressure engine, provision is made by which the latch is disengaged on every alternate revolution of the main shaft A This result is effected in thepresent instance by providing the rock-shaft (L with a crank orarm a, extended downward toward the rock-shaft a so that the crank or arm of may be engaged at theproper time by suitable cams, as will be described, so as to turn the rock-shaft a in its sleeve a and remove the latch-arm a from its operative position with relation to the head of the belt (4 Referring to Figs. 5, G, and 15, the bearinghub, supporting the rock-shaft (L20, is made of different diameters to form bearings 2 8 for the sleeve of and a lever a and for a sleeve or hub a, provided with a crank or arm a, the sleeve a having secured to it by a key a a grooved collar or ring a The grooved collar or ring a (shown separately in Figs. 7, 8, and 9) is provided with a projection a constituting one of the cams, which is adapted to engage the crank or arm a, and the lever (L55 is also provided with a thickened or cam surface a, (see Fig. 15,) which cam a is also adapted to be brought into engagement with the crank or arm a The grooved collar or ring (L59 is adapted to be moved longitudinally on the sleeve (1 in the direction indicated by the arrow 40, Figs. 6 and 15, so as to bringits cam-surface a into line with the crank or arm (L51 and to be moved in the direction opposite to that indicated by the arrow 40, so as to remove the cam projection a, which constitutes the tipping device for the latcharm a from in line with the crank or arm a. These movements of the grooved collar (1, and its cam a in accordance with this invention are automatically effected by the pressure of the gas admitted into the admission-valve cylinders, so that when the gas is of a constant or high pressure the cam a may be moved out of line with the crank or arm a in the direction opposite to that indicated by the arrow td-namely, into the position shown in Fig. 15-and when the pressure of the gas is reduced and it is desired the engine should operate under variable pressure the cam a will be moved into line with the crank or arm a and in the direction indicated by the arrow 40 and into the position shown in Fig. 6. The mechanism by which these movements of the sleeve 0. and its attached cam a are elfected may and preferably will be such as will now be described.

The grooved collar a is adapted to be engaged by ayoke a" (see Fig. 3,) having an arm a, which is pivoted, as at (1 on top of the valve-casing a and is connected at its upper end byalink or red 0, to a crank or armc fast on a rock-shaft a supported in suitable bearings a. on top of the engine-cylinder A and provided at one end with a crank or arm a to which is pivotally connected a pistonrod a (see Fig. 3) of a piston a (see dotted lines, Fig. 3,) contained in a cylinder a, provided at its lower end with a gas-inlet pipe a, which communicates, as herein shown, by

a branch pipe a with a chamber a with which directly communicate the valve-casings a and a and which chamber is provided, as shown in Fig. 3, with ahigh-pressure supply-pipe a and a low-pressure supply-pipe (L91, the high-pressure supply-pipe 0. being provided, as herein shown, with a throttlevalve a, and the low-pressure supply-pipe 0. being provided with an automatically-operated valve to. The main supply-piped is adapted to be connected with a suitable piston b and force the same downwardagainst reservoir containing gas or gas and air under high pressure, and the pipe a is adapted to be connected with a suitable reservoir con-v taining gas or gas and air under a lower pressure. These reservoirs are not herein shown, as they form no part of my invention and are well known.

From the above description it will be seen that the pressure in the cylinder (4 acting on the under side of the piston is the same as that in the chamber a and that when the gas of high pressure is supplied to the chamber 60 it is admitted to the cylinder (L85 and acts to move the piston (L upward in the direction indicated by the arrow 60, Fig. 3, which upward movement rocks the shaft ct. in a rearward direction and by means of the link a draws the grooved collar-a and its attached cam a into the position shown in Fig. 15-that is, so that the cam a is moved out of line with the crank or arm c0 and as long as the pressure of the gas is sufficient to keep the piston (L85 elevated the cam a will be held in its withdrawn position with relationto the crank or arm to and the admission and exhaust valves of the engine will be operated from the main eccentric through the wrist-plate a. When the cam (I160 is withdrawn from in line with the crank or arm a the engine is operating as a constant-pressure engine and the gas or gas and air admitted into the cylinder behind the piston when the latter is at one end thereof is exploded by means of an igniter B, which may be of any usual or suitable construction and communicating with the outlet port or passage 1) (see dotted lines, Fig. 1) from the valve-casing a. The valve of the igniter B has connected to its valve-rod Z) (see Fig. 3) a piston 5 located in a cylinder b provided at its upper end with a gas-inlet pipe 19 which is connected to the pipe a so that high-pressure gas may be admitted into the cylinder 12 above the the action of a spring I), located in the said cylinder. The downward movement of the piston 12 by the high-pressure gas serves to keep the igniter-valve constantly open as long as the engine is working as a constantpressure engine. When, however, the pressure of the gas is diminished, the spring acts on the piston 19 and closes the ignitervalve, and the latter is then opened at the proper time to enable the engine to be worked as a variable-pressure engine, as will be described.

WVhen the engine has been started asa constant-pressure engine and is running in the proper manner, the throttle-valve a may be closed and the proper connection made with the reservoir containing the gas and air under low pressure, which is admitted into the chamber a through the pipe a, the valve a being automatically opened by the pressure of the gas and held open against a stop descends and moves the rock-shaft (L77 and by means of the link connection a and yoke 00 moves the cam-collar 60 in the direction indicated by the arrow 40 and places the cam. ortipping device (4 into line with the crank or arm a, (see Fig. 6,) so that on every alternate revolution of the main shaft a the cam a is engaged with the crank or arm a and is moved in thedirection indicated by the arrow 20, Fig. 5, so as to carry the crank or arm (1 and the latch-arm (L34 in the direction indicated by the arrow 80, Fig. 5, which will trip or remove the latch from operative position with relation to the head 00 on the bolt a and thereby enable the sleeve a to be rocked on its bearing 2 without engaging the latch (L with the head (L32 of the bolt, and consequently without lifting the valve a The collar to may be rocked at alternate reciprocations of the piston A as herein shown by one of two eccentrics 12 Zr, mounted on a shaft 1), suitably supported in the framework of the engine and provided with a large gear W, which meshes with a pinion or gear b of one-half its size, fast on the main shaft A so that the shaft Z2 may make one revolution to every two revolutions of the main shaft. In the present instance I have represented the eccentric b as operatively connected to the collar a so as to rock the same,

the said eccentric being joined by a link or rod 12 to one end of a lever Z9 pivoted at b and having its other end joined by a link or rod Z7 to the crank or arm a of the collar a. The eccentric b is connected in a similar manner by link 19 lever Z9 pivoted at 11 and link or rod ()33 to the crank a of the collar a, governing the operation of the admission-Valve a at the opposite end of the cylinder A.

The eccentrics Z1 Z1 constitute the auxiliary or variable eccentrics and are connected to the cranks a, which govern the operation of the exhaust-valves a a at the opposite ends of the cylinder A, the crank a for the exhaust-valve a being connected, as herein shown, by link I) and lever b to the rod Z2 while the crank 0. for the exhaust-valve a i senses a a are also operatively connected to the governor G, which may be of any usual construction and which, as herein shown, has its movable sleeve b joined by a link b to a crank D on a rock-shaft 19 having a crank I), which is joined by a rod or link 17 to the lever a, the said lever having the cam a, as shown in Fig. 3, an arm I), joined by a link I) to the lever a for the admissionvalve a This connection with the governor enables the amount of gas admitted into the cylinder A to be controlled according to the speed of the engine, for when the speed of the engine is normal the cam a remains inactive with'relation to the arm (L51, but when the speed becomes excessive the said cam is brought into position to act on the arm a, and thereby disengage the latch-arm a from the crank-arm a before the valve 0, has been opened to its fullest extent, consequently diminishing the amount of gas admitted into the cylinder, and thereby reducing the speed to normal, and when this normal condition has again been attained the valve (0 is opened wide by the latch-arm d. Then the engine is running as a variable-pressure engine, it is required that the valves for the igniters B B should be operated at the proper time, which is effected by placing the said igniter-valves under the control of the eccentrics W 19 The connection between the eccentrics b Z7 and the igniter-valves may and preferably will be accomplished as herein shown and as will now be described.

Referring to Figs. 1, 2, and 3, the levers Z1 D have connected to them one end of rods or links Z2 I), joined at their opposite end to levers 12 B pivoted, as at 19 I1 and having arms I) i9 which have a sliding engagement with the valve-rods b I) of the igniter-valves and which are adapted to engage collars Z1 If on said valve-rods to open the ignitervalves against the action of the springs b. The collars Z2 12 are placed on or secured to the valve-rods, so that the arms I) I1 maybe moved up and down on the valve-rods without engaging. said collars when the engine is running as a constant-pressure engine, the pressure admitted into the cylinders 19 above the pistons 6 moving the collars Z2 Z3 down beyond the range of movement of the arms Z2 D but when this pressure is reduced the springs b close the igniter-valves and bring the collars b I) up into position to be engaged by the arms b 11 which operate at the proper time to open the igniter-valves and explode the charge compressed within the cylinder A, as is now practiced in fourcycle gas-engines.

I have herein shown and described one mechanical construction and arrangement whereby a gas-engine may be started as a constant-pressure engine and be automatically converted by diminution of pressure into a variable-pressure engine; but I do not desire to limit my invention to the precise mechanical construction shown. Furthermore, the invension-valve at one end and the exhaust-valve at the other end of the cylinder work in pairs. The val-ve-casin gs an. are provided with suitable devices to prevent flashing back, and in the present instance these devices are shown as a series of pencils, rods, or pins f, projecting from a cap or plate f, adapted to be bolted to the top of the valvecasings, the said pencils or rods being arranged in circles, as shown in Figs. 10 and 11, and having the same effect as the well-known wire-gauze or perforated plate to prevent the passage of the flame.

I claim-- 1. In a gas-engine, the combination of the following instrumentalities, viz: a cylinder provided with a gas admission valve, and with an exhaust valve, mechanism to actuate said valves, and means responsive to the pressure under which the engine is working to automaticall y operate said valve-actuating mechanisms and convert the engine automatically from a constant-pressure engine into a variable-pressure engine, substantially as described.

2. In a gas-engine, the combination of the following instrumentalities, viz: a cylinder provided with a gas-admission valve and with an exhaust-valve, actuating mechanisms for said valves, a main shaft, an eccentric on said shaft connected to said valve-actuating mechanism to operate it at every revolution of the main shaft, an auxiliary eccentric, and mechanism connected to said auxiliary eccentric and cooperating with said valve-actuating mechanism, and means operated by the-pressure of the gas admitted into said cylinder to render active the mechanism connected to the auxiliary eccentric and thereby control the operation of the valves, substantially as described.

3. In a gas-engine, the combination of the following instrumentalities, viz: a cylinder provided with a gas-admission valve and with an exhaust-valve, actuating mechanisms for said valves, mechanism operated by a predetermined pressure to place the said valve-actuating mechanism in condition to be operated to open the valves at each complete reciprocation of the piston in said cylinder, and

responsive to a diminution from said predc-.

termined pressure to place said valve mechanism in condition to be operated to open the valves at alternate reciprocations of said piston, substantially as described.

4. In a gas-engine, the combination of the following instrumentalities, viz: a cylinder provided with a gas-admission valve and with an exhaust-valve, a gas-igniter controlling the ignition of the gas admitted into said cylinder, valve-actuating mechanisms for said admission and exhaust valves, a wrist-plate connected to said valve-actuatin g mechanisms, a main eccentric connected to said wrist-plate,

means cooperating with the valve-actuating mechanisms and responsive to a predetermined pressure to render said valve mechanisms responsive to each revolution of the said main eccentric, an auxiliary eccentric, and means connected to said auxiliary eccentric to render the valve-actuating mechanism responsive only to alternate revolutions of the main eccentric, substantially as described.

5. In a gas-engine, the combination of the following instrumentalities, viz: a cylinder provided with a gas-ad mission valve and with an exhaust-valve, actuating mechanisms for said valves, each comprising a rock-shaft a connected to the valve and provided with a crank or arm a having a projection a, a sleeve c provided with a crank 03 a rockshaft a carried by said crank and provided with a latch or arm a to engage the projection (0 and with an arm a, a sleeve a provided. with a crank or arm, a collar keyed-on the sleeve a and provided with a cam, means to rock the sleeve a to lift the valve, means responsive to the pressure of the gas to move the said collar on the sleeve a to move its attached cam into and out of line with the crank or arm a, and means to rock the sleeve a, substantially as described.

6. In a gas-engine, the combination of the following instrumentalities, viz: a cylinder provided with a gas-admission valve and with an exhaust-valve at its opposite ends, a gasignit-er cooperating with each of said gas-ad mission valves, a valve-actuatin g mechanism for each of said admission and exhaust valves, a piston in said cylinder, a main shaft to which said piston is connected, a main eccentric on said main shaft, a wrist-plate connected to said main eccentric and to which the actuatin g mechanisms for said valves are connected, auxiliary eccentrics driven from the main shaft and revolving at a slower speed than the main eccentric, a trippingdevice for each of said valve-actuating mechanisms operated by said auxiliary eccentrics, means to operatively connect the valves of said igniters to said auxiliary eccentrics, and means responsive to the pressure of the gas admittedinto said cylinder to render the tripping device active or inactive according to said gas-pressure, substantially as described.

7. In a gas-engine, the combination of the following instrumentalities, viz; a cylinder provided with a gas-admission valve and with an exhaust-valve at its opposite ends, a gasigniter cooperating with each of said gas-admission valves a valve-actuating mechanism for each of said admission and exhaust valves, a piston in said cylinder, a main shaft to which said piston .is connected, a main eccentric on said main shaft, a wrist-plate connected to said main eccentric and to which actuating mechanisms for said valves are connected, auxiliary eccentrics driven from the main shaft and revolving at a slower speed than the main eccentric, a tripping device foreach of said valve-actuating mechanisms operated by said auxiliary eccentrics, means to operatively connect the valves of said igniters to said auxiliary eccentrics, and means respon sive to the pressure of the gas admitted into said cylinder to render the tripping device active or inactive according to said gas-pressure, a second tripping device for the gas-admission valves, and a governor connected to said second tripping device substantially as described.

8. In a gas-engine, the combination of the following instrumentalities, viz: a cylinder provided with a gas-admission valve and with an exhaust-valve, actuating mechanisms for said valves, and tripping devices for said admission and exhaust valves responsive to the pressure of gas employed to run the engine to automatically change the engine from a' constant-pressure to a variable-pressure engine, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses. p

' LOUIS J I-IIRT. Witnesses JAs. I-I. CHURCHILL, J. MURPHY. 

